function DragDropListObject(element,func){
  var x,i,j;
  this.debug=false;
  this.isDragging=false;
  this.listContainer=element;
//  this.listContainer.dragDropObject=this;
  if(func) this.onDragEnd=func;
  else this.onDragEnd=new Function();

  this.dragList=new Array();
  x= this.listContainer.childNodes;
  var instance=this;
  for(i=0; i<x.length; i++){
    if(x[i].nodeType==1){
      j=this.dragList.length;
      this.dragList[j]=new DragObject(x[i]);      
      this.dragList[j].onDragStart=function(){instance.dragStart(this.container);}      
      this.dragList[j].onDrag=function(p,o){instance.drag(o);}
      this.dragList[j].onDragEnd=function(){instance.dragEnd();}      
    }    
  }
}

DragDropListObject.prototype.dragStart=function(item){
  if(!this.isDragging){
    this.nowMoving=item;
    var h=this.nowMoving.offsetHeight;
    var w=this.nowMoving.offsetWidth;
    this.moveStyle=new Object();
    this.moveStyle.position=this.nowMoving.style["position"];
    this.moveStyle.width=this.nowMoving.style["width"];
    this.moveStyle.height=this.nowMoving.style["height"];

    this.placeHolder=ce('div');
    this.placeHolder.className="dd-place-holder";
    this.listContainer.insertBefore(this.placeHolder,this.nowMoving);
    this.nowMoving.style["position"]="absolute";
    this.placeHolder.appendChild(this.nowMoving);
    DHTML.setElementSize(this.nowMoving,w,h);
    DHTML.setElementSize(this.placeHolder,w,h);
    this.isDragging=true;
  }
}


DragDropListObject.prototype.dragEnd=function(){
  if(this.nowMoving&&this.placeHolder){
    this.nowMoving.style["position"]=this.moveStyle.position;
    this.nowMoving.style["width"]=this.moveStyle.width;
    this.nowMoving.style["height"]=this.moveStyle.height;    
    this.nowMoving.style["left"]="";
    this.nowMoving.style["top"]="";        
    this.listContainer.insertBefore(this.nowMoving,this.placeHolder);
    this.listContainer.removeChild(this.placeHolder);
    this.placeHolder=null;
    this.nowMoving=null;
    this.moveStyle=null;
  }    
  this.onDragEnd();
  this.isDragging=false;
}

DragDropListObject.prototype.drag=function(offset){
  var pOffset, sib, dif;
  if(this.placeHolder){
    pOffset=new Geometry.offsetBox(this.placeHolder);
    dif=offset.upperLeft.minus(pOffset.upperLeft).y;
    if(dif<0){
      sib=this.placeHolder.previousSibling;
      while(sib&&sib.nodeType!=1) sib=sib.previousSibling;
      if(sib&&sib.offsetHeight/2+3<-dif) this.listContainer.insertBefore(this.placeHolder,sib); 
    }else{
      sib=this.placeHolder.nextSibling;
      while(sib&&sib.nodeType!=1) sib=sib.nextSibling;
      if(sib&&sib.offsetHeight/2+3<dif) this.listContainer.insertBefore(sib,this.placeHolder); 
    }
  }
}

function DragDropObject(element,group){
  var x,i,j;
  this.debug=false;
  this.group=group;
  this.element=element;
  this.listContainer=element.parent;
  var instance=this;
  this.dragObj=new DragObject(this.element);      
      this.dragObj.onDragStart=function(){instance.dragStart(this.container);}      
      this.dragObj.onDrag=function(p,o){instance.drag();}
      this.dragObj.onDragEnd=function(){instance.dragEnd();}      

}

DragDropObject.prototype.dragStart=DragDropListObject.prototype.dragStart;
DragDropObject.prototype.drag=function(){
  this.dropTarget=null;
  for(var i=0; i<DragDropTargetList.length; i++){
    if(DragDropTargetList[i].group==this.group){
      if( Geometry.offsetBox(DragDropTargetList[i].element).inside(this.dragObj.dragCoordinate)){
        this.dropTarget=DragDropTargetList[i];
        DragDropTargetList[i].highlight(true);
      }else{
        DragDropTargetList[i].highlight(false);
      }
    }
  }
}
DragDropObject.prototype.dragEnd=function(){
  if(this.dragTarget){
    this.dragTarget.highlight(false);
    this.dragTarget.onDrop(this);
    this.dragTarget=null;
  }  
  if(this.nowMoving&&this.placeHolder){
    this.nowMoving.style["position"]=this.moveStyle.position;
    this.nowMoving.style["width"]=this.moveStyle.width;
    this.nowMoving.style["height"]=this.moveStyle.height;    
    this.nowMoving.style["left"]="";
    this.nowMoving.style["top"]="";        
    this.listContainer.insertBefore(this.nowMoving,this.placeHolder);
    this.listContainer.removeChild(this.placeHolder);
    this.placeHolder=null;
    this.nowMoving=null;
    this.moveStyle=null;
  }    
}

var DragDropTargetList=new Array();

 function DragDropTarget(element,group,func){
   this.element=element;
   this.group=group;
   if(func) this.onDrop=func;
   else this.onDrop=new Function();
 }